The sealing cap of a bung stopper closure of the type according to the species, which is described in EP 1 697 224 B1, for bung-type containers has elastic legs, which extend axially in the stopper depression and have a radially protruding foot. When the sealing cap is snapped onto the bung stopper, which is screwed into the bung connecting piece of a bung-type container, the elastic legs of the sealing cap plunge into the stopper depression and the leg feet lock with radial undercuts, which are formed on the base of the socket engagement eyes. The external diameter of the circularly situated leg feet of the sealing cap is greater than the internal diameter of the circularly situated, outwardly curved inner walls of the socket engagement eyes of the bung stopper having the undercuts for locking the leg feet of the sealing cap. This geometry of the closure stopper and the sealing cap results in difficulties when snapping the sealing cap onto the closure stopper in automatic filling plants for liquids, because the catch feet of the elastic legs of the sealing cap hit the upper edge of the socket engagement eyes of the bung stopper of the container to be closed at the beginning of the snapping procedure and are not guided by the inner walls of the socket engagement eyes of the bung stopper, but rather must be compressed far enough that the catch feet may engage with the inner walls of the socket engagement eyes.